<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_CSS显示模式</title>
    <style>
        div{
            width: 100px;
            height: 100px;
            border: red solid 5px;
            /*块级元素：默认竖着排 且可以设置宽高*/
            display: block;
        }
        span{
            /*行内元素 不能设置宽高 横着排*/
            display: inline;
            display: block;/*可以切换元素的显示模式*/
            background-color: yellow;
            width: 50px;
            height: 50px;
        }
        input,button{
            /*行内块 既能横着排又可以设置宽高*/
            display: inline-block;
            width: 100px;
            height: 100px;
        }
        .d2:hover{
            /*元素消失*/
            display: none;
        }
    </style>
</head>
<body>
<div class="d1">111</div>
<div class="d2">222</div>
<div class="d3">333</div>
<hr>
<span class="s1">123456789</span>
<span class="s2">123456789</span>
<span class="s3">123456789</span>
<hr>
<input type="text">
<input type="text">
<input type="text">
<button>按钮</button>
</body>
</html>